mmc: sdhci-tegra: Use actual clock rate for SW tuning correction

mmc: sdhci-tegra: Use actual clock rate for SW tuning correction

Ensure tegra_host member "curr_clk_rate" holds the actual clock rate
instead of requested clock rate for proper use during tuning correction
algorithm. Actual clk rate may not be the same as the requested clk
frequency depending on the parent clock source set. Tuning correction
algorithm depends on certain parameters which are sensitive to current
clk rate. If the host clk is selected instead of the actual clock rate,
tuning correction algorithm may end up applying invalid correction,
which could result in errors

Fixes: ea8fc5953e8b ("mmc: tegra: update hw tuning process")
Signed-off-by: Aniruddha TVS Rao <anrao@nvidia.com>
Signed-off-by: Prathamesh Shete <pshete@nvidia.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20221006130622.22900-4-pshete@nvidia.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>